Various pump features are provided. In a first aspect, a pump is provided having an actuator with a nozzle and a releasable cap having a first shield located to entrap a fixed volume of air about the nozzle. In a second aspect, a valve seat is located along a pump's internal fluid passage with deflectable spring arms extending therefrom that are deflectable in response to movement of a check valve element. In a third aspect, a compliant shut-off valve feature is provided, wherein, a first end of a tubular piston is deflectable in response to interferingly engaging the head of the poppet. In a fourth aspect, a pump includes a pump inlet, and a reservoir having a first portion and a second well portion in open fluid communication. Fluid may be trapped within the well portion at various angular orientations of the pump.